Efficacy of anastrozole in the treatment of hypogonadal, subfertile men with body mass index ≥25 kg/m2

Impact of GLP-1 Agonists on Male Reproductive Health-A Narrative Review

Background and objective-Obesity is a prevalent health concern that notably impairs male fertility through hormonal disruptions and other pathophysiological alterations. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) can significantly reduce weight. This narrative review synthesizes the existing literature discussing the impact of glucagon-like peptide-GLP-1 RAs on the male reproductive system, particularly on the hypothalamic-pituitary-gonadal axis and spermatogenesis, highlighting their potential impact on male fertility. Material and methods-PubMed database was used for the retrieval of English-language articles published up to November 2023. This non-systematic literature review predominantly concentrates on both pre-clinical and clinical studies pertaining to GLP-1 RAs, specifically exploring their impact on male reproductive hormones and sperm parameters. Results-GLP-1 receptors have been identified within the male reproductive system according to the existing literature. While the exact mechanisms are not well understood, they appear to be involved in glucose homeostasis and energy metabolism, both vital processes in spermatogenesis. Multiple clinical trials have demonstrated the efficacy of GLP-1 RAs for promoting weight loss. Recent studies show that the use of GLP-1 RAs in obese males may enhance sperm metabolism, motility, and insulin secretion in vitro, along with positive effects on the human Sertoli cells. Recent clinical trials discussed in this review demonstrate weight loss associated with GLP-1 RAs is correlated with improvements in sperm count, concentration, and motility. However, the direct impact of GLP-1 RAs on male reproductive hormones remains unclear, necessitating further research to confirm their potential role in treating male infertility. Conclusions-This narrative review summarizes the existing literature discussing the potential impact of GLP-1 RA on the male reproductive system, emphasizing their potential therapeutic role in addressing idiopathic infertility in obese men. Despite numerous studies exploring the influence of GLP-1 and GLP-1 RAs on reproductive hormones, testicular function, and spermatogenesis, further clinical trials are crucial to validate initial evidence. Longer follow-up periods are essential to address uncertainties regarding the long-term repercussions and outcomes of GLP-1 RA use. While this holds true, the current literature suggests that GLP-1RAs show promise as a potential therapeutic approach for improving sperm parameters in obese men.

Testosterone and luteinizing hormone predict semen parameter improvement in infertile men treated with anastrozole

OBJECTIVE

To identify patient factors associated with a clinically significant improvement in semen parameters among infertile men treated with the aromatase inhibitor anastrozole.

DESIGN

Multi-institutional retrospective cohort study.

SETTING

Two Tertiary Academic Medical Centers.

PATIENTS

A total of 90 infertile men treated at 2 tertiary academic medical centers who met inclusion criteria and obtained pretreatment and posttreatment semen analyses.

INTERVENTION

Prescription of anastrozole (median 3 mg/wk).

MAIN OUTCOME MEASURES

Upgrade in the World Health Organization sperm concentration category (WHO-SCC). Univariate logistic regression, multivariable logistic regression, and partitioning analyses were performed to identify statistically significant patient factors capable of predicting treatment response.

RESULTS

With anastrozole treatment, 46% (n = 41/90) of men responded favorably with a WHO-SCC upgrade, and 12% (n = 11/90) experienced a downgrade. Responders exhibited lower pretreatment levels of luteinizing hormone (LH, 4.7 vs. 8.3 IU/L) and follicle-stimulating hormone (4.7 vs. 6.7 IU/mL), higher pretreatment levels of testosterone (T, 356 vs. 265 ng/dL), and similar baseline level of estradiol (E2, 73% vs. 70% with detectible level). Baseline semen parameters differed, with anastrozole responders demonstrating higher baseline semen concentration (3.6 vs. 0.3 M/mL) and higher total motile sperm counts (3.7 vs. 0.1 M). Anastrozole therapy converted 29% (n = 26/90) of the cohort to normozoospermia and enabled intrauterine insemination access in 31% (n = 20/64) of previously ineligible patients. Interestingly, neither body mass index nor the baseline E2 level or E2-T ratio was associated with WHO-SCC upgrade. Multivariable logistic regression revealed the T-LH ratio (odds ratio: 1.02, 95% confidence interval: 1.00-1.03) and baseline nonazoospermia (odds ratio: 9.4, 95% confidence interval: 1.1-78.9) to be statistically significant predictors of WHO-SCC upgrade (area under receiver operating characteristic curve: 0.77). The final user-friendly partitioning model consisting of the T-LH ratio ≥100 and baseline non-azoospermia was 98% sensitive and 33% specific for WHO-SCC upgrades (area under the curve: 0.77).

CONCLUSION

Anastrozole therapy decreases serum E2 levels, increases serum gonadotropins, and clinically improves semen parameters in half of men with idiopathic infertility. Nonazoospermic infertile men with T-LH ratios ≥100 are likely to benefit from anastrozole treatment irrespective of baseline E2 level or E2-T ratio. Men with azoospermia rarely respond to anastrozole and should be counseled on alternative treatments.

Medical management of male infertility: now and future

PURPOSE OF REVIEW

Medical therapy for idiopathic male infertility has historically been empiric and based on small observational studies rather than larger well designed clinical trials. This review is timely and relevant because of the recent publication of several studies that are less susceptible to bias because of being placebo-controlled and more highly powered.

RECENT FINDINGS

The largest proportion of recent publications covered antioxidants, with eight randomized controlled trials (RCTs) included in this review. The Males, Antioxidants, and Infertility (MOXI) trial is of particular interest, being a large multicenter RCT, which demonstrated no improvement in semen parameters or live-birth rates with antioxidant use. In addition, phosphodiesterase-5 inhibitors (PDE5i) have been shown to improve semen parameters, while duloxetine use was not associated with any adverse effects on sperm. Progress was also made in the realm of regenerative medicine, with the realization of the first successful primate model of sperm production from pluripotent stem cells.

SUMMARY

It may be time to stop recommending antioxidants for idiopathic male infertility given recent studies suggesting lack of efficacy, but given their relative safety, it is reasonable to continue their use until the evidence is overwhelming. Otherwise, stem cell therapy is another anticipated area of research interest.